This application is based on Japanese Patent Application No. 2000-255592 filed on Aug. 25, 2000, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a rotary electric machine.
2. Description of Related Art
JP-B-2927288 discloses an alternator for vehicle as a rotary electric machine, which has a plurality of segments and a plurality of joining portions between the segments. In this arrangement, although almost all of the segments are regularly arranged on a stator core, a few segments are irregularly arranged and provide irregular connections and leads. These irregular segments might be more stressful, easier damaged, or worn down, as compared to the regularly arranged segments.
One aspect of the present invention addresses these drawbacks by providing an improved arrangement of a rotary electric machine.
According to a first embodiment of the present invention, a stator winding has a plurality of segments. The segments comprise a plurality of regular segments regularly arranged to provide a part of the stator winding and an irregular segment disposed to provide a remaining part of the stator winding. The segments are covered with insulating layers that comprise a first insulating layer covering a first surface of the segments and a second insulating layer covering a second surface of the segments. The second insulating layer has a higher insulation performance than the first insulating layer. The second surface, which is covered with the second insulating layer, relates to an insulation to the irregular segment, and is smaller than the first surface. Therefore, it is possible to prevent a short circuit involving the irregular segments by using less material that provides the second insulating layer.